/*
 * Copyright 2017-2020 original authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package io.micronaut.docs.server.filters;

// tag::imports[]
import io.micronaut.context.annotation.Requires;
import io.micronaut.http.HttpRequest;
import io.micronaut.http.MutableHttpResponse;
import io.micronaut.http.annotation.Filter;
import io.micronaut.http.filter.HttpServerFilter;
import io.micronaut.http.filter.ServerFilterChain;
import org.reactivestreams.Publisher;
import reactor.core.publisher.Flux;
// end::imports[]

@Requires(property = "spec.filter", value = "TraceFilter")
// tag::clazz[]
@Filter("/hello/**") // <1>
public class TraceFilter implements HttpServerFilter { // <2>
    private final TraceService traceService;
    public TraceFilter(TraceService traceService) { // <3>
        this.traceService = traceService;
    }
    @Override
    public Publisher<MutableHttpResponse<?>> doFilter(HttpRequest<?> request,
                                                      ServerFilterChain chain) {
        return Flux.from(traceService
                .trace(request)) // <4>
                .switchMap(aBoolean -> chain.proceed(request)) // <5>
                .doOnNext(res ->
                    res.getHeaders().add("X-Trace-Enabled", "true") // <6>
                );
    }
}
// end::clazz[]
